266 ALASKAN GLACIER STUDIES The Main Ice Cliff. The main ice cliff of Columbia Glacier, between the west shore and Heather Island, has a width of a little over two and a half miles. It is somewhat less impressive than the Hubbard Glacier cliff in Yakutat Bay, being shorter, less active, and with less imposing mountains behind. It is, however, a beautiful, pinnacled (PI. CV) and crevassed, snowy white, sinuous precipice of ice, rising vertically between 100 and 250 feet above the water, and in a less precipitous cascade to 500 feet. Its height, sweep and beauty may be inferred from PL CIV where the dimensions of the ocean steamship in the foreground give a scale for visualizing this magnificent ice cliff. It descends to an unknown depth below sea level, the nearest sounding being 600 feet, though the water may be a little deeper at other points. For various reasons, notably the sloping front of the ice cliff, the absence of large icebergs, and the shallowness of the water, we are convinced that the glacier front is not afloat. If it were, the water would need to be at least 1500 feet deep. In 1899 Gilbert stated1 that" at the western margin of its principal tidal cliff the glacier rested on a bank of drift at the level of low tide, and this bank extended eastward as a shoal,2 on which bergs were stranded, for several hundred yards from the shore. We noted two important streams from the western ice cliff. One of them issued from a cave at the water's edge near the western limit of the cliff, the other from a submerged and invisible tunnel near the middle of the (Jiff. The last mentioned was probably the largest of all the draining streams. It rose to the surface at the base of the cliff and flowed southward over the salt water, forming a broad lane of milky fresh water with a visible current and at times nearly free from floating ice." In 1909 and 1910 the streams mentioned were no longer there, doubtless having been destroyed by closing of orifices in the ice during the advance then in progress. The site of the shoal mentioned was overridden and there was no stranding of icebergs near the western margin except as ice masses had slid down from the cliff and lay upon the beach or near it in shallow water. Grant and Higgins* map of Columbia ice front (Fig. 81), made in June, 1909, shows a retreat of parts of the west cliff of nearly one-eighth of a mile, since 1899, ťOp. cit., pp. 76-76. * See Fig. 29. This was shown on his plane table map, but omitted in the reproduction in the Harriman Expedition report, Vol. D3, PL XI. FIG. 81. ADVANCE or COLUMBIA. GLACEBB FBOM 1899 TO 1909. LBTTEBS SHOW LOCATION OF PHOTOQBAPHIO STATIONS (AJTEB GRANT AND HIGGINB).